Portable bridge



Jab. -16, 1945.

R. G. LE TOURNEAU PORTABLE BRIDGE Filed Sept. 22, 1941 4 Sheets-Sheet 1 INVENF'OR.

ATTORNEYS Jan. 16, 1945.

R. G. LE TOURNEAU PORTABLE BRIDGE Filed Sept. 22, 1941 4 Sheets- Sheet 2 INVENTOR. R. 6'. Le Yurn sea A TTOR'NEYS Jan- 16, 1945. R. G. LE TOURNEAU PORTABLE BRIDGE Filed Sept. 22', 1941 4 Sheets-Sheet 3 INVENTOR. R.G.L87Zmrneau,

A TTORNEYS R. 6. LE TOURNEAU 2,367,291

-PORTABLE BRIDGE Filed Sept. 22, 1941 4 ShQets-Sheet 4 Jan. 16, 1945;

INVENTOR. R. 6. Le Yburn eau 4 TTORNEYS Patented Jan. 16, 1945 UNITED STATES PATENT OFFICE 2,357,291 7 PORTABLE BRIDGE Robert G. Le Tourneau, Peoria. Ill., assignor to R. G. Le Tourneau, Inc.,-a corporation pplication September 22, 1941, Serial No. 411,829

Claims.

This invention relates. in, general to a bridge or overpass structure, and in particular the invention is dire ted to a portable and sectional bridge arranged so that th sectional parts or spans of the structure may be transported in.

knocked-down or separated condition to the point of use and there assembled in bridge form.-

, One of the objects oi. this. invention is to pro-. vide a'portable and section-al'bridge whose structure islof' relatively low weight, and of such Sim-1 plicityjthat the several sections may be readily the above defined type which is also admirably adapted for use as a general 'traffic overpass at street or highway intersections so as to expedite and speed up traffic flow at such intersections.

.These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the fiollowing v specification and claims.

transported to the point oi use and rapidly as I sembled, as is desirable, for example, if used 'ior military or other emergency purposes; the bridge whenassembled being capable of supporting relatively heavy-loads. Another object of the. invention is to construct the separate spans of the bridge so that they are interchangeable as to their relative positions in the structure, which not only facilitates setting up of-the structure, but makes possible the useof dii-r.

ferent length spansv at any point in the bridge where. necessary.

A further" object is the provision of a unique.

supporting leg unit for each span; such unit when in use depending from a pivotal connection with the span and held rigid by adjustable kneebraces; these knee-braces being detachable at one end t permit the leg, unit, together with the braces; to fold against the bottom of the span whereby the spans canv bestacked one upon theother and thus transported,

It is also an object to arrange the spans so that the leg units can. be attached adjacent either or both ends of such spans; and further to provide coupling or connecting means at the ends of the spans which are operative to couple adjacent. span ends regardlessof which ends of the spansare brought together; these jeatures speeding the assembling operation of the legs on the spans,

and the connection of spans oi. thebridge.

An additional. object is to so construct the side beams or girders of the spans that-in use; they ,function notonly as supporting membersbutalso as wheel guardswhioh prevent hub caps ienders, and. running boards. from engaging the bridge, and revent tire from. being scufied 'IZhe structure of. the. spans further embodies a novel feature in the manner in which the box beam floor joists are connected with the side beams orgirdersfthe' use of: connecting irons-or; straps being eliminated, and inaddition the load. on each sioistis distributed or transmittedthrough; th side girders to the other joists of; the span.

'A further object is to provide a structure of 1y used on hinge bolts to initially secure aline-' together at adjacent ends as at 2, and supported legunit attached and in position of use.

detached.

Figure 5 is a side elevation'of aramp, Figure 6 is .a fragmentary, enlarged, longitudinal section on line 6-45 of Fig. 2, showingthe.

mounting of a hinge ear and the bracing of the adjacent end portion of a span.

Figure 'l is a fragmentarytransverse section.

on line 1-! of Fig. 3. v

Figure 8 is a transversesection on line 8-8 of Fig. 3 showing the special taper extension initial-.

ment of the'hinge ears.

Figure 9 is a similar view showing one hinge bolt as secured in place.

Figure 10 is a cross section online Ill-l0 of Fig. 3. l I

Figure 11 is. a fragmentary transverse section of a modification and shows the side girders as connected to a special type of flooring.

Figure 12 is a longitudinal section on line Referring now more particularly to the characters of reference on the drawings, and particularly at present to Figs. 1 to 10, the structure in general comprise a plurality of spans l hinged by leg units 3 which connect with said spans ad.- jacent the. hinges; the outer ends of the endmost spans extending over the bank B, for exbridges. To facilitate passage of vehicles onto theendmost spans, each of the latter is fittedample,- of a stream bed S which thestructure with anapproach ramp 4 hinged at one endonto the adjacent end of the. span and restin at other end on the ground.

the.

Each of the spans I, which may be of any desired length, comprises transversely spaced side beams or girders of box beam construction which in cross section are of trapezoidal form; the outer plate So being vertical, the top plate 5b of lesser width but greater thickness than the bottom plate 50, and the inner plate 5d disposed at an upward and outward slope from its lower edge. The top plate 5b being thicker than the bottom plate 50, there is no loss of strength even though the top plate is relatively narrow.

The spans of the bridge are supported by the leg units heretofore generally indicated at 3 in Fig. 1; such leg units being attached to the spans adjacent one end of the latter and always in the Box beam joists B extend transversely in longisecured between each joist and top plate 5b thereabove. By reason of the above arrangement, a cantilever action is had on both ends of the box beam floor joist, imparting more strength to each joist because the wheel load on one joist is distributed or transmitted through the side girders to all. the other joists of the span.

Metal plate flooring 8 seats on and is welded to the joists and extends from end to end of the span between the inner girder plates St! to which it is likewise welded. As the inner platesid of the side girders slope upward and outward, an effective wheel guard is provided, preventing wheel or body contact, as well as tire scuffing.

The several spans of the bridge are hinged together by means of the following:

Ears 9 of plate form are secured on edge against and depend from the bottom plate 50 of the side girders and project longitudinally beyond the ends of the latter; these ears being elongated and provided with an upstanding tongue 9a which projects through a slot into and is secured to the irder between the end joist 6 and a transverse reinforcing plate I. In order that the spans can be connected together regardless of which ends thereof are brought together, a pair of spaced ears 9 project from opposite ends of opposite side girders, and the remaining opposite ends of such girders have a single ear disposed to project snugly between the pair of ears which will be adjacent and on the next span (see Fig, 2). These ears 9 are formed with matching holes in through which bolts ll engage when the hinge ears are brought into position. In order to make the holes in the ears match correctly, and to facilitate placement of bolts ll, an elongated taper head I! is threaded on each bolt; the shank of the bolt and head being of the same diameter. The bolt and taper head is driven through the holes in the engaged ears 9, the taper head providing a lead which assures proper alinement of the ears and ready placement of the bolt. When the bolt is in place, the taper head is removed and a conventional nut substituted therefor as shown in Fig. 9,

The ramps 4 are of much the same construction as the spans l, except that at their free end portions and at the bottom they are beveled or feather out for ground engagement, as shown at l3 in Fig. 5. Transversely spaced ears l4 project longitudinally from and in a plane below the inner ends of the rampsj such ears l4 being disposed for cooperative and bolted engagement with ears 9 on the adjacent end of the corresponding spans, being provided with horizontal base plates Ma which form bank or ground bearing members.

same corresponding position on the diiferent spans. Each leg unit, as shown particularly in Figs. 3 and 4, comprises transversely spaced box beam legs arranged in rigid, parallel relation by means of cross bracing l6. At their upper end the legs l5 are fitted with upstanding ears l7; there being a pair of such ears on one leg in spaced relation, and a'single one of such ears on the other leg. The spacing of the legs and position of ears I1 is such that the latter cooperate with ears 9 on the corresponding span at either end; the pair of ears I! straddling a single one of ears 9, and the single ear ll projecting between a pair of cars 9; there being a pivot bolt l8 passing through matching holes in cooperating ears 9 and I1. formed back of holes H] for the span connecting bolts. A taper head, the same as head l2, may

7 be used to lead bolts l8, and to align the holes of ears 9 and I1.

Knee braces I9, which include a turnbuckle 2U, connect diagonally between the upper portion of each leg l5 and a bracket 2| secured on the bottom plate 56 of the corresponding side girder. These braces are connected at the ends to the leg and bracket by means of cap bolts 22 passing through eyes 23 on the ends of the braces and threaded into said legs and brackets; the underface of the head of bolts 23 being tapered and seating in a taper seat in the corresponding eye,

I as at 24. The bolts and eyes are thus self-alining,

and the bolt holes in the eyes can thus be made oversize to facilitate starting of the bolts into the threads, all as is shown in Fig. 10.

As the braces H! are adjustable in length, they can be set to position the leg units vertical and compensate for any given slope of the spans; these braces being strong and effectively maintaining the leg units in place. When the bridge spans are disconnected for transport, the braces l9 are detached at one end and the leg units, together with said braces, are folded against the, bottom of the spans and the latter stacked for transportation in such position.

It will be noted that brackets 2| are mounted on each span adjacent each ear or pair of ears 9, and that each ear has a hole H] for a leg mounting bolt l8. By reason of this arrangement, a pair of legs may be mounted under any one span (particularly the center one), if desired, in whichcase no legs would be necessary on the adjacent ends of adjacent spans. It should also be noted that the adjustability of braces I9 is suflicient to enable them to extend from a leg mounted on the ear 9 of one span to the connecting bracket 2! on the adjacent span, insteadof to the bracket on the same span as shown inthe drawings.

The bridge is erected across a stream bed or the like by means of wheeled crane equipment such as shown in U. S. Patent No. 2,281,507. The so quence followed is for an initial span to be placed with one end on the bank B and the other end overhanging the stream bed S; th leg unit being on said other end and is swung down and secured in position by the knee braces. Thereafter the crane equipment, which carries the remaining.

spans, moves onto the first erected span, from their sets and connects the second span, then moves onto the second span and thus continues span erecting operations until the other bank of the stream is reached.

The leg attachmentholes in ears 9 are.

flooring is of relatively light weight and yet quite strong and in some instances may be used instead of the metalplates 8. As this open flooring, indicated at 25, includes a plurality of transverse I beams 26 in spaced, parallel relation, the joists 6' previously described are eliminated, and the flooring extends from side to side ofthe span and into the side girdersZ'I to a termination at the outer plates 21a thereof and resting on the bottom plates z'lc; being secured to both thereof as by welding. The inner plate 21d of the side girders extend at an upward and outward-slope from longitudinallyextending shoes or strips 23 secured atop the flooring 25. Top plates 21b connecthorizontally between the inner and outer plates to complete the side girders. Vertical reinforcing plates 29 are secured transversely within the side guides, being symmetrical to the interior thereof and engaging or seating on the upper edge of said I beams 26. A finish channel 30 connects the side girders 2'! at their ends, and if necessary a longitudinal supporting beam 3i may be applied to the underside offiooring 25 centrally between the side girders.

While I have here shown thebridge as being made up of three spans, for purposesof illustration, it will be obvious that as many spans may be used as conditions may require, not only to span a given distance but to avoid, if desired, any considerable angle being formed between adjacent spans, and which would interfere with the desired smoothness of vehicle movement.

This latter factor is especially to be taken into consideration when the structure is erected as an overpass for general motor vehicle trafiic at a street or highway intersection.

From the foregoing description it will be readily seen that I have produced such a structure as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the structure, still in practice such deviations from such detail maybe resorted to'as do not form a de parture from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

1. A portable bridge comprising a plurality of separate spans disposed in end to end relation,

means detachably connecting adjacent ends of said spans together in rigid relation transversely, supporting leg units, and means foldably securing said leg units on and beneath certain of the spans for holding against the bottom thereof, and releasable means normally preventing folding of the leg units from a span supporting position; said last named means comprising knee braces extending diagonally from the leg units to the span, said knee braces each including a turnbuckle assembly.

2. A- portable bridge comprising a plurality of separate spans disposed in end to end relation, means detachably connecting adjacent ends of said spans together in rigid relation transversely, supporting legunits, means pivoting the leg units on certain of the spans for folding movement lengthwise and against the bottom thereof, and

longitudinally adjustable braces connected between said leg units and said spans in releasable relation, said braces normally securing the leg units in rigid and supporting relation to the spans.

3. A portable bridge comprising a plurality of separate spans disposed in end to end relation, means detachably connecting adjacent ends of the spans in rigid relation transversely, supportting leg units for certain spans, said units including transversely spaced legs, means pivoting said legs at their upper end on the spans at transversely spaced points, and diagonal longitudinally adjustable knee braces extending lengthwise of the spans and pivotally connected between said legs and the spans, said braces normally maintaining the'leg units in rigid supporting relation to the spans.

4. A portable bridge comprising a plurality of separable spans disposed in end to end relation, transversely spaced ears secured on the spans and projecting from the ends thereof, ears projecting from adjacent ends of the spans cooperatively engaging, means pivoting said cooperating ears together, a supporting leg unit for certain for connection at its upper end to the adjacent one of said attachment elements. v

5. A portable bridge comprising a plurality of spans in end to end relation, means detachably connecting adjacent ends of said spans, supporting legs secured in connection with certain of said spans, an approach ramp at the outer ends of the endmost spans, and means connecting ad-- jacent ends of said ramps and endmost spans; said means including transversely spaced ears on the ramps, said ears being formed to provide ground engaging shoes.

ROBERT G, LE TOURNEAU. 

